The present invention relates to a device for holding components that are made of a ferromagnetic material, are arranged consecutively in a row and are held in place with one contact surface resting against at least two adjacent magnetic poles of opposite polarity, with the magnetic lines of force between the magnetic poles being concentrated in a region close to the contact surface of the components without magnetically influencing the working surfaces opposite the contact surfaces.
A device of this type is used for holding components, which, for example, are only partially coated in an electroplating bath on their ends facing away from the contact surfaces. In this case, the device is limited to only one row of consecutive components, and the magnetic poles of alternating polarity each extend across the entire row.
Magnet strips and pole strips can be used for this purpose. With a device of this type, the components do not have to have a sufficient residual magnetic field on their working surfaces to hold ferromagnetic particles in place. The attracted and held particles would cause beads to form during coating, which would prevent the component from being used in the coated region, due to the latter""s poor surface quality.
Devices of this type are often used to machine very small components in large quantities. Arranging the components in only one row results in an unwieldy device when a large number of components need to be machined at the same time.
An object according to an exemplary embodiment of the present invention is to provide a device that preamble which can be used to greatly increase the number of components to be held and worked simultaneously without having to deal with disadvantageous residual magnetic fields on the component working surfaces.
This objects may be achieved according to an exemplary embodiment of the present invention by arranging multiple rows of components parallel to one another and assigning to the outer rows of components additional magnetic circuits that divert or compensate for the residual magnetic field of the working surfaces of these components.
According to an exemplary embodiment, a large number of components can be arranged and held magnetically in place in parallel rows without producing, particularly in the outer rows, disadvantageous magnetic fields that would make it impossible to work components in these outer rows. The entire grid can be fitted with component holders. Despite the considerably greater number of components to be held, the device can be produced with a compact design. The additional magnetic circuits on the outer rows, which take up little space and do not add much to the cost, can help avoid disadvantageous residual magnetic fields on the component working surfaces. The only thing to keep in mind is that the additional magnetic circuits must have the same polarity as the adjacent magnetic poles in the outer rows of components.
According to an exemplary embodiment, the layout of the magnetic circuits is designed so that at least one magnet strip, held in place between two pole strips and magnetizing the latter with the opposite polarity, extends across each row of components; and the pole strips, together with the magnet strips held between them, form the magnetic poles of alternating polarity for the assigned row of components, with the adjacent magnetic poles of the pole strips in adjacent rows also having the same polarity. Standard magnet strips and standard pole strips can be used in this manner to construct the device.
According to an exemplary embodiment, the adjacent pole strips in adjacent rows can be spaced a certain distance apart. However, the adjacent pole strips can also lie directly against one another and can be combined in each case to form a common pole strip.
To hold magnet strips and pole strips in position, the magnet strips and pole strips are held by a contact plate in a cartridge that faces the contact surface of the components, with this contact plate being provided with grooves in the region of the magnet strips; and the grooves extend across the assigned row of components and are provided in the side of the contact plate facing the contact surfaces of the components. The grooves in the contact plate guide the main field between adjacent magnetic poles of opposite polarity over the held component and not over the electrically and magnetically conductive contact plates
If the additional magnetic circuits are formed by additional magnet strips that rest against the outer pole strips of the outer rows of components and magnetize the latter with the same polarity as the magnet strips assigned to the outer rows of components, the same magnet strips can be used for the additional magnetic circuits, and they need only to be added on, taking the polarity into account.
To maintain the same magnetic values in the regions of the additional magnetic circuits, the contact plate extends beyond the additional magnet strips and is provided with correspondingly assigned grooves; and the distance between the additional magnet strips and the magnet strips of the outer rows of components is approximately half the distance between the magnet strips of adjacent rows of components.
To magnetically terminate the additional magnetic circuits, according to an exemplary embodiment, the additional magnet strips can be terminated by an additional pole strip on the side facing away from the rows of components.
If the contact plate extends beyond the additional magnetic circuits with their magnet strips and, together with at least one magnet strip and two pole strips, forms in each case a magnetic holding circuit for spacing elements which carry a holding plate provided with guide and cover holders for the components, the device can be equipped with additional means, also held magnetically in place, for guiding and covering the components.
Because the contact plate is also used as an electrical connection for the electroplating bath, the contact plate according to an exemplary embodiment is made of a ferromagnetic material with a gold-plated and rhodanized surface that is resistant to the treatment medium for the components.